Fine needle aspiration biopsy (FNAB) is a rapid and cost-effective procedure that uses a syringe to sample fluid from a cyst or remove clusters of cells from a solid mass for diagnostic purposes. The effectiveness of FNAB is operator-dependent and the diagnostic yield could be low, especially for adipose- rich tissue and masses where the percentage of non-diagnostics aspirates is relatively high (15-20%). Proper needle placement could substantially reduce the number of the non-diagnostic aspirates and therefore improve the diagnostic yield of the procedure. Advanced techniques now exist to do FNAB guidance, like stereotactic CT or ultrasound, but they are expensive, require additional personnel and they are not always available in small clinics. Physical Sciences Inc. (PSI), in collaboration with Masachusetts General Hospital (MGH), proposes to develop a simple and low-cost instrument based on Low Coherence Interferometry (LCI) that will be used as a guidance tool for needle placement during the FNAB procedure. In Phase I a pre-clinical system was developed and a pilot in vitro clinical study on various tissue specimens was conducted to demonstrate the capability of the system to differentiate tissue types (adipose, fibroglandular, and tumor). An animal study was performed as well to demonstrate the capability of the instrument to differentiate tissue-types in vivo. Phase II of the project will focus on the development of a portable, low cost clinical system with a disposable probe and an expanded clinical study on animals will be performed at the Massachusets General Hospital to prove the effectivness of the instrument in the guidance of FNAB procedures. PUBLIC HEALTH RELEVANCE: Low Coherence Interferometry is a proposed guidance tool for needle placement during an FNAB procedure of a breast mass. With this technology, the pathologist or biopsy physician performing the biopsy will be able to guide the needle to the most diagnostic area of the mass due to the instruments ability to determine the tissue type present at the tip of the needle before taking the sample. The hypothesis is that this technology will decrease the number of non-diagnostic aspirates by increasing the overall yield of tissue representative of the mass. Having confidence that the FNA sample is truly representative of the mass will not only help ensure that patients who do have cancer are properly diagnosed, but will allow patients who do not have cancer and their referring physicians to trust in the negative biopsy results thereby preventing additional, more invasive and unnecessary procedures.